From 07f5bb5c2476978d1142e37fcb9b2945e1406483 Mon Sep 17 00:00:00 2001
From: Harini Katakam <harini.katakam@xilinx.com>
Date: Wed, 18 May 2022 22:37:56 +0530
Subject: [PATCH 13/19] net: macb: Fix PTP one step sync support
Git-commit: 5cebb40bc9554aafcc492431181f43c6231b0459
Patch-mainline: v5.19-rc1
References: git-fixes

PTP one step sync packets cannot have CSUM padding and insertion in
SW since time stamp is inserted on the fly by HW.
In addition, ptp4l version 3.0 and above report an error when skb
timestamps are reported for packets that not processed for TX TS
after transmission.
Add a helper to identify PTP one step sync and fix the above two
errors. Add a common mask for PTP header flag field "twoStepflag".
Also reset ptp OSS bit when one step is not selected.

Fixes: ab91f0a9b5f4 ("net: macb: Add hardware PTP support")
Fixes: 653e92a9175e ("net: macb: add support for padding and fcs computation")
Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220518170756.7752-1-harini.katakam@xilinx.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 40 ++++++++++++++++++++++++++++----
 drivers/net/ethernet/cadence/macb_ptp.c  |  4 +++-
 include/linux/ptp_classify.h             |  3 +++
 3 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 89c253739822..606770d4bd33 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -35,6 +35,7 @@
 #include <linux/tcp.h>
 #include <linux/iopoll.h>
 #include <linux/pm_runtime.h>
+#include <linux/ptp_classify.h>
 #include "macb.h"
 
 /* This structure is only used for MACB on SiFive FU540 devices */
@@ -1155,6 +1156,36 @@ static void macb_tx_error_task(struct work_struct *work)
 	spin_unlock_irqrestore(&bp->lock, flags);
 }
 
+static bool ptp_one_step_sync(struct sk_buff *skb)
+{
+	struct ptp_header *hdr;
+	unsigned int ptp_class;
+	u8 msgtype;
+
+	/* No need to parse packet if PTP TS is not involved */
+	if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)))
+		goto not_oss;
+
+	/* Identify and return whether PTP one step sync is being processed */
+	ptp_class = ptp_classify_raw(skb);
+	if (ptp_class == PTP_CLASS_NONE)
+		goto not_oss;
+
+	hdr = ptp_parse_header(skb, ptp_class);
+	if (!hdr)
+		goto not_oss;
+
+	if (hdr->flag_field[0] & PTP_FLAG_TWOSTEP)
+		goto not_oss;
+
+	msgtype = ptp_get_msgtype(hdr, ptp_class);
+	if (msgtype == PTP_MSGTYPE_SYNC)
+		return true;
+
+not_oss:
+	return false;
+}
+
 static void macb_tx_interrupt(struct macb_queue *queue)
 {
 	unsigned int tail;
@@ -1199,8 +1230,8 @@ static void macb_tx_interrupt(struct macb_queue *queue)
 
 			/* First, update TX stats if needed */
 			if (skb) {
-				if (unlikely(skb_shinfo(skb)->tx_flags &
-					     SKBTX_HW_TSTAMP) &&
+				if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
+				    !ptp_one_step_sync(skb) &&
 				    gem_ptp_do_txstamp(queue, skb, desc) == 0) {
 					/* skb now belongs to timestamp buffer
 					 * and will be removed later
@@ -2022,7 +2053,8 @@ static unsigned int macb_tx_map(struct macb *bp,
 			ctrl |= MACB_BF(TX_LSO, lso_ctrl);
 			ctrl |= MACB_BF(TX_TCP_SEQ_SRC, seq_ctrl);
 			if ((bp->dev->features & NETIF_F_HW_CSUM) &&
-			    skb->ip_summed != CHECKSUM_PARTIAL && !lso_ctrl)
+			    skb->ip_summed != CHECKSUM_PARTIAL && !lso_ctrl &&
+			    !ptp_one_step_sync(skb))
 				ctrl |= MACB_BIT(TX_NOCRC);
 		} else
 			/* Only set MSS/MFS on payload descriptors
@@ -2120,7 +2152,7 @@ static int macb_pad_and_fcs(struct sk_buff **skb, struct net_device *ndev)
 
 	if (!(ndev->features & NETIF_F_HW_CSUM) ||
 	    !((*skb)->ip_summed != CHECKSUM_PARTIAL) ||
-	    skb_shinfo(*skb)->gso_size)	/* Not available for GSO */
+	    skb_shinfo(*skb)->gso_size || ptp_one_step_sync(*skb))
 		return 0;
 
 	if (padlen <= 0) {
diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
index c2e1f163bb14..c52ec1cc8a08 100644
--- a/drivers/net/ethernet/cadence/macb_ptp.c
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -469,8 +469,10 @@ int gem_set_hwtst(struct net_device *dev, struct ifreq *ifr, int cmd)
 	case HWTSTAMP_TX_ONESTEP_SYNC:
 		if (gem_ptp_set_one_step_sync(bp, 1) != 0)
 			return -ERANGE;
-		fallthrough;
+		tx_bd_control = TSTAMP_ALL_FRAMES;
+		break;
 	case HWTSTAMP_TX_ON:
+		gem_ptp_set_one_step_sync(bp, 0);
 		tx_bd_control = TSTAMP_ALL_FRAMES;
 		break;
 	default:
diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h
index 9afd34a2d36c..b760373524fe 100644
--- a/include/linux/ptp_classify.h
+++ b/include/linux/ptp_classify.h
@@ -43,6 +43,9 @@
 #define OFF_PTP_SOURCE_UUID	22 /* PTPv1 only */
 #define OFF_PTP_SEQUENCE_ID	30
 
+/* PTP header flag fields */
+#define PTP_FLAG_TWOSTEP	BIT(1)
+
 /* Below defines should actually be removed at some point in time. */
 #define IP6_HLEN	40
 #define UDP_HLEN	8
-- 
2.16.4